With the vigorous development of China's economy, there are more and more demands for electric energy. In order to meet the increasing demand of electricity in China, measures shall be taken to continue to expand in the direction of power line, high voltage and large capacity. On the one hand, with the construction of a large number of power lines, the coverage becomes much broader, terrain conditions are more complex and diverse, and it is difficult to figure out how to solve the problem of providing cross-terrain line maintenance. On the other hand, the environment of the power lines also constantly changes with the region and time. The whole power line system is complex, and the hidden danger in some key link may affect the users' power supply and system's power supply safety, resulting in immeasurable economic losses and threatening the safety of life and property, so power line inspection shall be deemed as an important part of power system equipment maintenance.
High-voltage power line, that is, overhead line, refers to the power line which erects the wires on the pole and tower with insulators and power fittings, and is an important component of the power grid and power system, which is vulnerable to external impacts and damages. At present, the overhead line accidents mainly include accidents due to external damages, wind accidents, lightning accidents and accidents caused by aging of equipment. The so-called accidents due to external damages mainly refer to accidents caused by foreign objects entering non-safe areas or distance, such as forest trees, housing construction and power lines in other non-safe areas, which not only poses a threat to the safety of power lines, but also easily leads to electric shock in the obstacle itself, fire hazard and other accidents. According to relevant reports, accidents due to external damage account for about one-fourth of the total number of trips of the national power lines, causing enormous harm and economic loss to the society.
The traditional power line inspection mode is usually manual inspection, which requires large consumption of manpower resources, but under the circumstance with large coverage of power lines and diverse needs for the environment, manual power line inspection has low efficiency and poor timeliness, as a result of which it often cannot meet the requirements for coverage and timeliness of power line inspection. In addition, the traditional manual power line inspection mode is often based on human eye observation and determines according to the staff experience in the status of the power line. Given its excessive dependence on the staff's status and experience, it cannot give a quantitative analysis of the distance between the obstacle and the power line and tends to cause false and missed inspection, so it cannot meet the accuracy requirement for power line inspection.